What are PROKARYOTES? TEM of dividing cell No true nucleus No chloroplasts No mitochondria other organelles They are ancient life forms known as bacteria.

Kingdom Monera

What are PROKARYOTES?

TEM of dividing cell

• No true nucleus• No chloroplasts

• No mitochondria other organelles

They are ancient life forms

known as bacteria

Two major classes of bacteria

Archaebacteria & Eubacteria

Methanogens Extreme Thermophiles Extreme Halophiles

Cyanobacteria (Blue-green algae) & other

Gram negative bacteriaGram positive bacteria

THE FOLLOWING ARE DIVISION

◦CYANOPHYTA-Blue green algae

PHYCOLOGY SLIDE SHOW

CYANOBACTERIA - the ‘Blue-Green Algae are in the kingdom monera

Some Characteristics of the Cyanobacteria

* Contain Chlorophyll a and carotenoids, plus the phycobilins (proteinaceous photosynthetic pigments) phycocyanin and phycoerythrin (c f. Rhodophyta), found in thylakoids

* Have cell walls of peptidoglycan, often with a mucilaginous sheath

* The carbohydrate stored is glycogen

* No flagella, but some exhibit gliding movements

* Some fix nitrogen in specialized cells called heterocysts

In some genera the mucilaginous sheath forms a gelatinous matrix

Gelatinous matrixIndividual cells

Gloeocapsa

Filaments of Nostoc commune forming a

gelatinous ball

Bacteria that are:

• Photosynthetic (convert light energy to food)

• Produce O2 as a byproduct of photosynthesis

• Some have capacity to fix N2 into NH4

• Some produce toxins

• Some have formed millions of years old stromatolites as living structures

Division Cyanophyta

TEM of dividing cell

Cyanophytes have changed the path of evolution on earth

General features

150 genera2000 species,

Habitats:virtually everywhere

Oceans Freshwater

Soil Hotsprings

Epiphytes

Gram negative bacteria

Morphological Range:

Endophytes

Cell Walls:

Ancient organisms but well suited to earth’s habitats

Unicells to complex multicell organisms

Trichodesmium blooms can cover 2x106 km2 and be seen via satellites NASA

Diversity

DIVISION CYANOPHYTA

CLASS-CYANOPHYCEAEORDER-CHROOCOCCALES

GloeocapsaMerismopediamicrocystis

ORDER-OSCILATORIALESOscilatoriaLyngbyaNostocAnabaena

Order Chroococcales

Merismopedia

Diversity

Microcystis

Diversity Order Nostocales

Growth &morphology Order Nostocales

False branching1. Rupture of sheath and cells

:

2. Remaining cells at both ends continue to grow

3. Both trichomes push through weakened sheath

What to look for?

Is there a change in the plane of cell division?

New Cell Types

Nitrogen fixation supports protein synthesis1. Low N in environment

2. Cell differentiates as a specialized cell, the heterocyst

3. Creates setting for Nitrogenase enzyme

4. Enzyme converts N2 NH4+

polar heterocysts

Order Nostocales

Growth &morphology Order Nostocales

Nitrogen fixation & Azolla in rice fields replace fertilizers1. Low N in environment

2. Heterocysts differentiate

3. Enzyme converts N2 NH4+

4. Water fern benefits from fertilizer

intercalary heterocysts

5. Rice fields are more productive

Other cell types Order NostocalesAkinete

Anabaena

Order Nostocales

Cool stuff

Blue green algae

merismopedia

oscillatoria

gloeocapsa

Nostoc

Nostoc

Nostoc

Anabaena

Anabaena

Anabaena

Anabaena

THE END